Many studies have examined the interactions between mesofauna and
ectomycorrhizal fungi. Setälä (1995) reported that by consuming ectomycorrhizal
fungi, soil mesofauna may influence development of plant–fungus symbioses.
Mesofauna can also affect the dynamics of the symbiosis between ectomycorrhizal
fungi and vascular plants (Moore et al. 2003). Mesofauna feeding on
ectomycorrhizal fungi has been shown to increase primary productivity of the host
plants (Harris and Boerner 1990; Setälä 1995). As the rate of ectomycorrhizal
infection increases, photosynthetic rates in leaves and often plant size increase as
well (Allen 1991; Staddon et al. 1999). Furthermore, ectomycorrhizae can mediate
the interactions between fungus-feeding mesofauna and aboveground herbivores
(White 1984; Price 1991). Although studies have shown that the ecological significance of fungus-feeding mesofauna can reach far beyond the rhizosphere (Moore
et al. 2003), data are lacking on mesofaunal relationships with sclerotia-forming
ectomycorrhizal fungi. Given the ability of sclerotia to survive for long periods of
time, information on these ectomycorrhizal fungi may also contribute to our understanding of sclerotia life history. Furthermore, understanding sclerotia and their
associations with mesofauna may lead to a better understanding of the complex
food web and biological processes in the soil.
3.2 Community Profiles of Ectomycorrhizal Fungi
Consumed by Soil Mesofauna
3.2.1 Materials and Methods
3.2.1.1 Study Area and Soil Sampling Techniques
The location and characteristics of the study sites are given in Table 3.1. Forest soil
samples were collected from 10 Â 10 m
2 plots in the five study areas: Akita, Iwaki,
Chokai, Nagano, and Minamiosawa. At each site, nine cylinders, each with a
capacity of approximately 800 cm
3 , were used to obtain soil from the A horizon to
10 cm depth for mesofauna extraction (Fig. 3.2).
3.2.1.2 Soil Mesofauna Extraction
Soil samples for mesofauna extraction were transported in cotton bags to ensure that
mesofauna remained viable until extraction. Soil mesofauna were extracted using a
modified Berlese–Tullgren funnel (Macfadyen 1953). The basic principle of a
Berlese–Tullgren funnel is to create a temperature gradient over a soil sample in
an attempt to force mobile organisms to move away from the higher temperature and
fall into a collecting vessel. In this study the heat was produced by a 5 W light bulb
and the heat gradient was increased by placing an aluminum funnel (14 cm in length)
around the soil sample. The collecting vessel was filled with 70% ethanol for surface
3 Relationships Between Soil Mesofauna, Ectomycorrhizal Fungi, and Sclerotia in. . .
37
ectomycorrhizal fungi. Setälä (1995) reported that by consuming ectomycorrhizal
fungi, soil mesofauna may influence development of plant–fungus symbioses.
Mesofauna can also affect the dynamics of the symbiosis between ectomycorrhizal
fungi and vascular plants (Moore et al. 2003). Mesofauna feeding on
ectomycorrhizal fungi has been shown to increase primary productivity of the host
plants (Harris and Boerner 1990; Setälä 1995). As the rate of ectomycorrhizal
infection increases, photosynthetic rates in leaves and often plant size increase as
well (Allen 1991; Staddon et al. 1999). Furthermore, ectomycorrhizae can mediate
the interactions between fungus-feeding mesofauna and aboveground herbivores
(White 1984; Price 1991). Although studies have shown that the ecological significance of fungus-feeding mesofauna can reach far beyond the rhizosphere (Moore
et al. 2003), data are lacking on mesofaunal relationships with sclerotia-forming
ectomycorrhizal fungi. Given the ability of sclerotia to survive for long periods of
time, information on these ectomycorrhizal fungi may also contribute to our understanding of sclerotia life history. Furthermore, understanding sclerotia and their
associations with mesofauna may lead to a better understanding of the complex
food web and biological processes in the soil.
3.2 Community Profiles of Ectomycorrhizal Fungi
Consumed by Soil Mesofauna
3.2.1 Materials and Methods
3.2.1.1 Study Area and Soil Sampling Techniques
The location and characteristics of the study sites are given in Table 3.1. Forest soil
samples were collected from 10 Â 10 m
2 plots in the five study areas: Akita, Iwaki,
Chokai, Nagano, and Minamiosawa. At each site, nine cylinders, each with a
capacity of approximately 800 cm
3 , were used to obtain soil from the A horizon to
10 cm depth for mesofauna extraction (Fig. 3.2).
3.2.1.2 Soil Mesofauna Extraction
Soil samples for mesofauna extraction were transported in cotton bags to ensure that
mesofauna remained viable until extraction. Soil mesofauna were extracted using a
modified Berlese–Tullgren funnel (Macfadyen 1953). The basic principle of a
Berlese–Tullgren funnel is to create a temperature gradient over a soil sample in
an attempt to force mobile organisms to move away from the higher temperature and
fall into a collecting vessel. In this study the heat was produced by a 5 W light bulb
and the heat gradient was increased by placing an aluminum funnel (14 cm in length)
around the soil sample. The collecting vessel was filled with 70% ethanol for surface
3 Relationships Between Soil Mesofauna, Ectomycorrhizal Fungi, and Sclerotia in. . .
37